How Was China's Tiangong-1 Space Station Crash Tracked So Accurately?

How Was China's Tiangong-1 Space Station Crash Tracked So Accurately?  Space.com Chinese space lab burns up on re-entry over Pacific Ocean  Spaceflight Now How to avoid sharing fake photos of the space station that just crashed into Earth  Popular Science Malfunctioned Chinese Space Station Crashes Back To Earth  ValueWalk Chinese space station plunges into the ocean. No one hurt, no one there.  Washington PostFull coverage